1. Field of the Invention
This invention is generally directed to machines for coating and laminating sheet materials and more specifically to an apparatus for positively feeding varying sizes of paper, cardboard or metallic sheet materials which may be imperforate or perforate to coating rollers wherein the material may be selectively coated on either or both sides so as to varnish, plasticize or glue the material and wherein the material may thereafter be laminated with a second material which may be in the form of a web of plastic which would cover any perforations or opening in the primary base material. The invention is further directed to the use of a coating machine which incorporates a cutter assembly which may be utilized to sever the treated and laminated materials to preselected lengths. The invention further incorporates the use of specially aligned and mounted applicator cylinders which insure that the varnish, glue or plasticizing agent does not contaminate the rollers or cylinders as the sheet material passes therebetween.
The present invention is directed to a device for coating and plasticizing sheet materials which may have openings or perforations and which may be paper, cardboard, carton, metal or plastic materials wherein the materials are fed by a simplified feeding head which prevents the sheet material from being misfed to the coating rollers or cylinders. The invention is further directed to improving the production of graphical materials and boxes utilizing plasticizing, polishing and varnishing agents which are applied to one or both sides of sheet material and which are applied in such a manner as to increase the production rate and decrease the overall production costs with respect to such manufacturing.
2. History of the Related Art
Heretofore, it has taken four or more devices to coat sheet materials utilized in various box or other manufacturing operations. Therefore, with the present invention, an improvement in operating costs and space savings is achieved which reduces the overall cost of carton and box manufacture. The invention is particularly directed to manufacturing cartons which may include openings or windows which are covered by a laminate or thin plastic material. Further, the present invention is easy to operate and may be utilized by relatively unskilled persons which is contrary to the prior art devices which require a great deal of personnel training.
The quality of the finished sheet materials of the present invention is excellent and the quantities of production can be increased over the prior art while still achieving a cost reduction in manufacturing. This is especially true with plasticized sheets which have glue applied thereto nd thereafter are immediately pressed against a transparent plastic laminate film and rolled tightly so as to reduce the amount of glue consumption utilized in the laminating process. Further, the present invention may be utilized with glues which are water soluble and odorless, inexpensive to purchase and fireproof so that the glues will not adversely effect the local environment and will reduce manufacturing costs normally associated with glues which utilize solvents which must be evaporated during the laminating process.
Prior to the present invention, manufacturing containers or boxes utilized sheet feeding systems which were extremely complicated and involved high production costs. Further, conventional feed systems for coating and laminating machines have frequently encountered problems resulting in misfeeding of the materials to the coating units resulting in loss of manufacturing time and materials. This is especially true with feeding mechanisms which are not designed to accommodate varying sizes of sheet material. In many instances, sheet materials will be misfed or introduced in an improper alignment with the coating cylinders or feed devices passing the materials to the coating cylinders thereby resulting in damage to the material in the manufacturing process. Also, many prior art feeding mechanisms were not adequately designed to feed sheet materials having openings or which were perforated such as materials which are utilized to manufacture boxes or cartons having packing windows incorporated therein. With many feed mechanisms, the individual sheets of material which are stacked near the feed assembly will bind with one another especially if openings are provided in the material for the creation of packing windows. As one sheet is moved relative to the stack, the edge defining the opening or perforation in the material has a tendency to engage portions of the underlying materials thereby misfeeding or misaligning the sheet as it is moved toward the coating assemblies. This misfeeding is further complicated when the sheet materials have become distorted or warped due to improper packaging or climatic conditions.
In addition, prior art coating machines conventionally use cylinders and revolving drums having teeth incorporated therewith for holding the sheet material as it passes adjacent to a coating cylinder. In many instances, material which is fed into the coating cylinders may stick with the drum or the teeth associated therewith as the drums and teeth become contaminated with glue or other materials being applied to the sheet material as it passes in relationship to the coating cylinders and pressure cylinder or drums. The problem of drum or cylinder contamination is further complicated in those instances where the pressure cylinder contacts and is in direct alignment with the coating cylinder so that coating materials are applied directly to the pressure cylinder surface in the absence of sheet material passing therebetween. This results in further contamination of the pressure cylinder and will result in the misaligning and misfeeding of the sheet materials passing between the pressure cylinder and the coating cylinder. In these instances, the cylinders must be cleaned in order to prevent fouling of sheet materials passing between the pressure and coating cylinders. This cleaning requires that the equipment be shut down for a period of time thereby reducing production. Further, if different sizes or shapes of sheet material are to be utilized, regulation and setting of the spacing between the drums or pressure cylinder and coating cylinders is often necessary. Such adjustment further reduces the downtime of the machine and therefore loss in production.
A further problem with prior art laminating type equipment utilized in coating and laminating machinery is that the material to be laminated is frequently coated with a material that must be heated to remove solvents or reduce the amount of moisture on the film material prior to its being pressed to the underlying base material. The heat needed for such operations increases costs and complicates the overall assembly in that shrinkage of the laminate film may occur especially with the use of glues containing solvents. Further, when watery glues are used, they are slow drying and tend not to stick together thereby not providing a satisfactory bond between the overlying film and the base material.
Another problem prevelant in prior art coating and laminating machines is that the coating, gluing, varnishing or other material being applied to the sheet material is not maintained in a uniform liquid phase thereby creating differences in application rates and bondings between various materials. As the machine is operated, the coating material may have a tendency to settle within the primary bowls which feed the coating cylinders thereby effecting the overall application rate and bonding characteristics of the coating material. Further, in many systems, there is no means provided for recycling the adhesive or coating materials and such materials are frequently not only wasted but also present problems in clogging or contaminating the interface between the application rollers and pressure cylinders which feed sheet material relative to the coating cylinders.
Another problem associated with prior art coating machinery which is utilized to sever generally continuous laminating films applied over separate base sheet materials is that the cutting mechanisms become fouled due to the application of glue or other coating materials along the continuous length of the laminate sheet even though the underlying layers are spaced relative to one another. If the cutter mechanism becomes fouled, then the overall operation and production rate is significantly reduced with the cleaning of the cutter mechanisms becoming necessary.